[NLRS] satelite positioner arms

[Dr. Gerald N. Johnson]

VE4MA showed how to use an electric scissor jack for elevation adjust on 
his home tower top dish. I think without looking, CSVHF 2006, maybe MUD 
2008.

The limitations with a linear actuator as an azimuth rotor is that with 
a simple lever arm on the rotation mast, angle is not a linear function 
of actuator linear position and that less than 180 degrees of motion is 
the maximum possible. But by adding a curved link as in this back hoe 
bucket with a linear hydraulic cylinder it's possible to curl about 270 
degrees. I've not worked out the angle vs stroke, I'm sure its quite 
nonlinear.
static.ddmcdn.com/gif/backhoe-loader-sideview.jpg

There are places like McMaster-Carr who sell linear actuators with racks 
on the end to drive gears to spin shafts linearly. Somewhere a worm gear 
box gets to be simpler.

73, Jerry, K0CQ

On 4/26/2015 5:03 PM, Dr. Gerald N. Johnson wrote:
>
>
> There several at Axeman University.
>
> Another source with greater variety is Surplus Sales in Lincoln Nebraska
> who has a good web page. They know load rating, tarvel, and voltage but
> freight adds to the cost.
>
> 73, Jerry, K0CQ
>
> On 4/26/2015 1:44 PM, Doug Reed wrote:
>>
>>
>> I think it was during the April breakfast that talk got around to
>> questions about how to position a tower mounted 10GHz dish, or maybe
>> it was for moon-bounce. One suggestion was to use the linear
>> positioners from an old C-band dish. Then the question was where to
>> get them. I suggested that many satellite dealers advertising on Ebay
>> still sell linear positioners. Here is one Ebay listing for a 24 inch
>> positioner for $50. Within the listing are links for a couple more
>> units. How to mount and use them is left as an exercise for the
>> user.... :-)
>>
>> 73, Doug Reed, N0NAS.
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